Persisting or Worsening Impulse Control Disorders in Parkinson's Disease Following a Switch to Subcutaneous Foslevodopa‐Foscarbidopa

BACKGROUND: Impulse control disorders (ICDs) are most often associated with dopamine agonists and pulsatile dopamine replacement therapy such as oral levodopa and subcutaneous apomorphine. Intestinal levodopa-carbidopa gel may improve ICDs through rationalization of dopaminergic agents and/or a reduction of pulsatile dopaminergic stimulation, however the impact of subcutaneous foslevodopa/foscarbidopa (CSFLI) has not been reported to date. CASES: We describe five men aged 50-68 with advanced Parkinson's disease (PD) and pre-existing ICDs who were switched to CSFLI. Four of them were transitioned directly from subcutaneous apomorphine infusions with the hope of improving ICD symptoms. All experienced worsening or persistent ICD symptoms, predominantly hypersexuality, after switching to CSFLI with a mean time to peak ICD symptoms of 4.5 weeks (range 2-6). CONCLUSIONS: CSFLI may exacerbate ICDs in susceptible individuals. Pre-treatment screening and close monitoring are recommended.